The authors made the electrochemical studies on the electrode processes during copper electrodeposition with ionic liquids-reline as an electrolytic medium. Reline is a commercial name for a eutectic mixture of cholin...The authors made the electrochemical studies on the electrode processes during copper electrodeposition with ionic liquids-reline as an electrolytic medium. Reline is a commercial name for a eutectic mixture of choline chloride and urea（1：2, molar ratio）. This new proposed method of copper deposition is an ecological one because the ionic liquids are recyclable, non-volatile and non-toxic. Cyclic voltammetry investigations were conducted at 343 and 353 K in choline chloride-urea（Reline） deep eutectic solvent with single salt CuCl（generally in 0.05--0.38 mol/L concentration range）. Electrochemical impedance spectroscopy investigations were conducted in choline chloride- urea ionic liquid with CuCI（0.05 mol/L）. We investigated both cathodic and anodic processes of Cu＋ ions at different sweep rates in this new electrolytic system based on choline chloride. We have proposed by this an alternative to the classical copper electrodeposition. Coefficient of diffusion, Do, for the system Reline-CuCl is presented and the value of D0 is 1.22× 10^-8 cm2/s.展开更多
The gravimetric analysis of electrodeposited nickel is demonstrated using electrochemical quartz crystal microbalance (EQCM) where the nickel coatings come from a solution of the metal chloride salt separately in eith...The gravimetric analysis of electrodeposited nickel is demonstrated using electrochemical quartz crystal microbalance (EQCM) where the nickel coatings come from a solution of the metal chloride salt separately in either a1choline chloride: 2 ethylene glycol (ethaline) or 1 choline chloride: 2 urea (reline) based ionic liquid. The possibility of adapting the Quartz Crystal Microbalance EQCM (which measures the mass attached to the electrode) to probe kinetics of electrochemically-driven solid state phase transformations has been explored in a Ni electrodeposition in absence and presence of complexing agents ethylene diamine en and acetylacetonate acac from both electrolytes ethaline and reline. The study shows that the current efficiency and the rate of deposition of nickel coatings obtained from ethaline and reline baths in absence of brighteners en and acac are different, and the addition of en and acac to both ionic liquid solutions results in a significant decrease current. And the associated growth rate will also be decreased, suggesting that the en acac stops the formation and growth of Ni nuclei. This suggests that the mechanism of growth is changed.展开更多
As changes in hard or soft oral tissues normally have a microbiological component,it is important to develop diagnostic techniques that support clinical evaluation,without destroying microbio-logical formation.The opt...As changes in hard or soft oral tissues normally have a microbiological component,it is important to develop diagnostic techniques that support clinical evaluation,without destroying microbio-logical formation.The optical coherence tomography(OCT)represents an alternative to analyze tissues and microorganisms without the need for processing.This imaging technique could be defined as a fast,real-time,in situ,and non-destructive method.Thus,this study proposed the use of the OCT to visualize biofilm by Candida albicans in reline resins for removable prostheses.Three reline resins(Silagum-Comfort,Coe Comfort,and Soft-Confort),with distinct char-acteristics related to wa ter sorption and fungal inhibition were used.A total of 30 samples(10 for each resin group)were subjected to OCT scanning before and 96 h after inoculation with Candida albicans(URM 6547).The biofilm analysis was carried out through a 2D optical Callisto SD-OCT(930 nm)operated in the spectral domain.Then,the images were preprocessed using a3×3 Gaussian filter to remove the noise,and then Otsu binarization,allowing segmentation and pixel counting.The layer's biofilm formed was clearly defined and,indeed,its visualization is modified by water sorption of each material.Silagum-Comfort and Soft.Confort showed some similarities in the scattering of light between the clean and inoculated samples,in which,the latter samples presented higher values of light signal intensity.Coe-Comfort samples were the only ones that showed no di®erences between the clean or inoculated images.Therefore,the results of this study suggest that OCT is a viable technique to visualize the biolm in reline materials.Becausendings in the literature are still scarcely using the OCT technique to visualize biolm in reline resins,further studies are encouraged.It should not contain any references or displayed equations.展开更多
文摘The authors made the electrochemical studies on the electrode processes during copper electrodeposition with ionic liquids-reline as an electrolytic medium. Reline is a commercial name for a eutectic mixture of choline chloride and urea（1：2, molar ratio）. This new proposed method of copper deposition is an ecological one because the ionic liquids are recyclable, non-volatile and non-toxic. Cyclic voltammetry investigations were conducted at 343 and 353 K in choline chloride-urea（Reline） deep eutectic solvent with single salt CuCl（generally in 0.05--0.38 mol/L concentration range）. Electrochemical impedance spectroscopy investigations were conducted in choline chloride- urea ionic liquid with CuCI（0.05 mol/L）. We investigated both cathodic and anodic processes of Cu＋ ions at different sweep rates in this new electrolytic system based on choline chloride. We have proposed by this an alternative to the classical copper electrodeposition. Coefficient of diffusion, Do, for the system Reline-CuCl is presented and the value of D0 is 1.22× 10^-8 cm2/s.
基金the Ministry of Science and Technology,the People's Republic of Bangladesh for financial support of this work(Grand Reference No.MOSICT/PRC-24/2009-2010/BS-52/172)
文摘The gravimetric analysis of electrodeposited nickel is demonstrated using electrochemical quartz crystal microbalance (EQCM) where the nickel coatings come from a solution of the metal chloride salt separately in either a1choline chloride: 2 ethylene glycol (ethaline) or 1 choline chloride: 2 urea (reline) based ionic liquid. The possibility of adapting the Quartz Crystal Microbalance EQCM (which measures the mass attached to the electrode) to probe kinetics of electrochemically-driven solid state phase transformations has been explored in a Ni electrodeposition in absence and presence of complexing agents ethylene diamine en and acetylacetonate acac from both electrolytes ethaline and reline. The study shows that the current efficiency and the rate of deposition of nickel coatings obtained from ethaline and reline baths in absence of brighteners en and acac are different, and the addition of en and acac to both ionic liquid solutions results in a significant decrease current. And the associated growth rate will also be decreased, suggesting that the en acac stops the formation and growth of Ni nuclei. This suggests that the mechanism of growth is changed.
基金This study is a palrt of the INCT/INFO(National Institutes of Science and Technology,Photonics National Institute-465.763/2014-6)is sup-ported by the CNPq/MCTI(National Council of Technological and Scientific Development and Ministry of Science Technology and Innov ation)+1 种基金the PRONEX program(Center of Excellence on Biophotonics and Nanophotonics-APQ-0504-1.05/14)sponsored by FACEPE/CNPq(Founda-tion for Science and Technology of Pernambuco State and National Council of Technological and Scientific Development).
文摘As changes in hard or soft oral tissues normally have a microbiological component,it is important to develop diagnostic techniques that support clinical evaluation,without destroying microbio-logical formation.The optical coherence tomography(OCT)represents an alternative to analyze tissues and microorganisms without the need for processing.This imaging technique could be defined as a fast,real-time,in situ,and non-destructive method.Thus,this study proposed the use of the OCT to visualize biofilm by Candida albicans in reline resins for removable prostheses.Three reline resins(Silagum-Comfort,Coe Comfort,and Soft-Confort),with distinct char-acteristics related to wa ter sorption and fungal inhibition were used.A total of 30 samples(10 for each resin group)were subjected to OCT scanning before and 96 h after inoculation with Candida albicans(URM 6547).The biofilm analysis was carried out through a 2D optical Callisto SD-OCT(930 nm)operated in the spectral domain.Then,the images were preprocessed using a3×3 Gaussian filter to remove the noise,and then Otsu binarization,allowing segmentation and pixel counting.The layer's biofilm formed was clearly defined and,indeed,its visualization is modified by water sorption of each material.Silagum-Comfort and Soft.Confort showed some similarities in the scattering of light between the clean and inoculated samples,in which,the latter samples presented higher values of light signal intensity.Coe-Comfort samples were the only ones that showed no di®erences between the clean or inoculated images.Therefore,the results of this study suggest that OCT is a viable technique to visualize the biolm in reline materials.Becausendings in the literature are still scarcely using the OCT technique to visualize biolm in reline resins,further studies are encouraged.It should not contain any references or displayed equations.
